1) Hormonal regulation of renal physiological and pathophysiologic functions. Specifically, we have investigated the regulation of renal cortical and medullary cyclooxygenase-2 (COX-2) expression by different hormones including elements of the renin-angiotensin system, dopaminergic system, adrenal corticosteroids, vasopressin, and others. We have also investigated the regulation of renal COX-2 by type II 11? hydroxysteroid dehydrogenase (11?HSD2) elevation of intracellular glucocorticoids. We are now intensively investigating the interaction between the intrarenal dopaminergic system and the intrarenal renin-angiotensin system using genetically manipulated mice with either elevated or reduced intrarenal dopaminergic activity.